You have to buy the bulky Sony Ericsson LiveDock to be able to use USB OTG on the previous version of SE cellphones like Arc S.(and it is likely for this cellphone)

On the other hand it mustn't be forget that USB ports always consume lots of power and drain the battery.(SRP protocol on OTG may compensate this defect just a little but any way, a USB is a USB and don't forget the battery has just 1320 mAh capacity).

I think 4gb is not too bad,becouse for exemple there is google musik,claud service music player, if you are realy that much hardcore and dont have the extra 200€ to spend on a phone.There is also dropbox that you can just hack in to,and purches 23gb of extra storege.
The 3.7inc screen is to small for watchin movies so the 4 gb is enauf for apps. I personaly have the 4gb sd and the samsung galaxy ace(thats 158mb of spece) and I used half of the memorie on the phone.
And you have the buetifull camera,1080p recording etc.
High end phone exept the memory for low price(for Europe its 249€,the Xperia P is 449€ and the Xperia S is 499€)
If you need more space there is always huawei with its low prices but good specs and no custum UI witch i personaly like a lot,especialy for the new 4.0 ics android version that has a beutifull UI.
Thats all hope hellps you deside.

Sony xperia u is a entry level phone ...and it has 4gb user accesible memory,2gb phone memory , 2 gb system memory.... So we can use 6gb out of 8gb ....and a very good point is it supports usb on the go. . . So people should not cry like a kid :p or still want something else than go for higher end phones and be ready for expese more and loose some cash from ur pocket ;)

abdul samad, 24 Mar 2012It Has Internal storage capacity has 512 MB of RAM and has the ability to expand upto 32 GB.Abdul, Sony Xperia U has only 8GB internal memory. User accessible memory will be around 4GB and No external memory slot is available.

2410, 25 Mar 2012without a card slot only 4 gb memory!!
this is epic fail .. !!!this is for people who don't give a damn about multimedia but wants a capable smart phone. this is going to be an entry level smart phone. you might look at this as a failure but for other people it hits the sweet spot.